When stuck in a traffic jam, wouldn’t it be nice to push a button and have a mask drop down from the automobile roof as in an airplane safety video, place it firmly over your nose and mouth, and breathe in a stream of pure fresh air?

In some cities, you’d probably want that filter mask on the whole time you’re on the road.

Because you’d be filtering only the small amount of air you and your passengers actually breath, instead of all the air in the cabin, then it would be economically justifiable to use a fancy filtering system, and even to fortify it with a little extra oxygen.